Fabrication of fluorescent hybrid nanomaterials based on carbon dots and its applications for improving the selective detection of Fe (III) in different matrices and cellular imaging.

Considering that detection on cations or ions still meets some challenges in achieving the effectivity and selectivity just by employing one platform, the ingenious fabrication of nanomaterials exhibits an increasing research interests for the preponderance in improving or integrating the performance of single platform. Herein, a fluorescent hybrid nanomaterials based on an organic dye 4-methylumbelliferone (4-MU) as modifier and D-arginine as carbon cores has been developed via a facile one-step hydrothermal synthesis, forming carbon dots (CDs)/4-MU hybrid nanomaterials (CDs-4-MU). This kind of nanomaterials can improve the sensitive and selective detection of single CDs towards Fe ions in different matrices. The detection mechanism of CDs-4-MU towards Fe can be attributed to an electron transfer process between CDs-4-MU and Fe, leading to the fluorescence quenching. The limit of detection (LOD) and corresponding linear range in tris-HCl buffer solution are 0.68 μM and 2.29-200 μM, respectively. Furthermore, this nanomaterial can also achieve a detection of Fe ions in real samples such as tap water, culture medium and fetal bovine serum. In particular, CDs-4-MU exhibits a good biocompatibility and can be uptaken by MC3T3 cells, thus can be applied for Fe ions detection in cellular level and cellular imaging. Therefore, this work provides a versatile strategy for the synthesis of CDs-based hybrid nanomaterials and opens a new pathway for improving the ion detection in real samples, which is of significance in practical applications.